Communication signal data collection is an increasingly important aspect of situational awareness, surveillance, spectrum monitoring and signal analysis with both military and civilian applications. Most recorded communication signal files have a very large data size due to the over-sampling in collection and massive recording of signal data with uncertain contents. Generally, some current computer or signal processing equipments or software afford only a very limited buffer size for data processing. Due to an order of magnitude size disparity between large communication signal files and limited data processing buffer sizes, the review, extraction, editing and search of the desired signal section in any large communication signal data file with uncertain contents is often a very lengthy, time-consuming and inefficient process. Additionally, the search and tailor procedures employed by the user are also quite labor intensive. Typically, a tedious and time-consuming repeated prescreen routine requires a user to load the large data file piece by piece into a small buffer for review until the user finally finds the desired data sample segment. One illustrative example of the disparity between the size of a large data signal file and a limited size working space buffer is 10 GB vs. 10 MB. Since the file content is unknown, the piece-by-piece loading and analysis is subject to human error and may miss the desired section.
Thus, there has been a long-felt need of software or hardware for processes and techniques that overcome the problems, disadvantages, limitations and shortcomings of Communication signal data collection techniques that require loading large data files piece-by-piece into a small buffer for further processing. An automated decimation method is needed to extract, edit or tailor large files efficiently in a fixed-size small buffer. The signal monitoring apparatus and methods using automated decimation ratios will satisfy the long-felt need for processes, apparatus and software that overcome the numerous problems, disadvantages, limitations and shortcomings of loading large data files into small buffer areas and the subsequent manual search during communication signal data collection. The present invention provides signal monitoring techniques for extracting data signal samples using an automatically adjusted decimation ratio provide a low resolution preview of the signal envelope, zoom in to the signal section of interest using the Graphic User's Interface (GUI) until getting desired resolution for extracting, analyzing and editing data files. The software and devices automatically adjust a decimation ratio that decimates, or trims, the size of the desired large data segment by reducing the over-sampling rate in order to fit into the buffer for further data processing, without suffering from the disadvantages, shortcomings and limitations of prior art techniques and devices.